Definition of "pi-meson" []

• A meson involved in holding the nucleus together; produced as the result of high-energy particle collision (noun)

WordNet. Princeton University. 2010.

• "The pi-meson, the messenger of the strong force that keeps the atomic nucleus together, has an unusual property."
• "Nambu's theory also claimed that the pi-meson was a composite particle – today we know that it is composed of quarks."
• "- The many pi-meson decaysresulted in a collimated beam of muons and neutrinos."